Electric heating system for cooking appliances



Feb. 10, 1948. C v WEBER 2,435,641 I ELECTRIC HEATING SYSTEM FOR COOKING APPLIANCES Filed June 29, 1944 20 I 20 BAKE P22502212 my. 2. my. 5.

IN VEN TOR H15 ATTORNEY Patented Feb. 10, 1948 ELECTRIC HEATING SYSTEM FOR COOKING APPLIANCES Victor Weber, Greensburg, Pa.,

ertshaw Thermostat Company,

assignor to Rob- Youngwood,

Pa., a corporation of Pennsylvania Application June 29, 1944, Serial No. 542,682

1 This invention relates to an electric circuit for'the heating elements of cooking appliances and, more particularly, to the control thereof to give various connections to the electric circuit I for preheating, baking and broiling operations.

Another obiect of the invention is to operate both top and bottom oven heating elements during a baking operation with a greater amount of heat emanating from the bottom.

Other objects and advantages will become apparent from the following description taken in 2 connection with the accompanying drawings, wherein Fig. 1 is a schematic view of a cooking appliance and switching mechanism embodying this invention: and

Figs. 2, 3 and 4 are wiring diagrams showing the electric circuits for bake, pre-heat and broil operations, respectively.

Referring more particularly to the drawings, the cooking appliance is shown in Fig. l in broken lines in the form of an oven l0 having a switch housing l2 associated therewith and also shown in broken lines as the constructional form of either is immaterial for the purposes of this invention. The heating devices comprise a broiling element l4, shown as located in the upper portion of the oven l0, and a multi-part baking element l6 shown as located in the lower portion thereof. One part l8 of the multi-part baking element [6 is preferably of higher resistance value than the other part thereof.

The switch housing l2 may be of any suitable type containing switching mechanism arranged for manual, thermostatic or any other desired form of operation. In this embodiment, the mechanism comprises two fixed contacts 22 and 24 spaced one from the other for cooperation with a pair of movable contacts 26 and 28, carried on a pair of movable switch arms 30 and 32, respectively, In addition, the switch arm 30 is provided on the side opposite the contact 26 with contact 34 which is movable into and out of engagement with a fixed contact 36 upon movement of the switch arm 30.

The contacts 2224 are connected to one line wire 38 of a source of electric power by wires 40 and 4| respectively. One end of the broiling element I4 is connected by a wire 42 to the other 3 Claims. (01. 219 2o) line 44 of the two-wire power system and the opposite end of the broiling element I4 is connected by a wire 46 to the switch arm 30. Similarly, one end of the part 20 of the multi-part baking element I6 is connected by a wire 48 to line wire 44 and the opposite end thereof is connected by a wire 50 to the switch arm 32. The other part [8 of the multi-part bakin element It is connected at one end by a Wire 52 to wire 50 and at the opposite end thereof is connected by a wire 54 to the fixed contact 36.

The switching mechanism is shown in the off position in Fig. 1, wherein both the broiling element l4 and the multi-part baking element [6 are disconnected from the source of electric power. In Fig. 2 the elements are shown as connected to the line for a baking operation which is accomplished by leaving contact arm 30 in the position shown in Fig. l and moving contact arm 32 to engage contacts 24--28. In this bake position it will be apparent that the part 18 of the multi-part bake element [6 having the high resistance value is connected to the source of electric power in series circuit with the broiling element 14 and the other part of the multi-part baking element [6 is connected in parallel therewith.

The purpose of the high resistance element [8 is now apparent as for reducing the current value to the broil element l4. By properly proportioning the part IS a desired amount of heat capacity can be obtained in the broil element l4 during the bake operation. Moreover, the part l8 serves to increase the emitted heat in the bottom of the oven l0 which would otherwise be solely governed by the capacity of the part 20.

In the preheat position of the switch mechanism the heating elements are connected to the line as shown in Fig. 3 of the drawings, the contacts 24-28 remaining engaged while the switch arm 30 is in position to engage contacts 26-22. Thus, only the part 20 of the multi-part bake element I6 is connected to the source of electric power by line wires 44-38 and the broil element I4 is connected in parallel therewith. As the part 20 and the broil element l4 are thereby connected at full line voltage the oven It) can be brought quickly up to temperature during this operation.

To conduct a broil operation, the broil element l4 only is connected to the lines 38 and 44 as shown in Fig. 4. The multipart bake element i6 is disconnected in this position by operating switch arm 32 for opening the contacts 24-28 while contacts 26-22 remain engaged. The heat which is available in this operation emanates from the broil element l4 and is thus concentrated at the upper portion of the oven 10 as is required for broiling purposes.

tion of a multi-part baking element, a broiling element, and switching means arranged in one position thereof to connect one part of said multipart element to the source in series circuit with It will be observed from the foregoing descrip- 5 said broiling element and another part of said tion of the various cooking operations that the multi-part element in parallel therewith, in anpart i8 of the multi-part baking element 16 is other posit on thereof to connect-only-one part never connected at full line voltage and is used of saidmulti-part element to the sourceland said only during the baking operation. This part l3 broiling element in parallel therewith, and in a can therefore be of inexpensive construction com- 10 third position to connect only said broiling elepared with the other part 20 of the multi-part ment to the source. bake element I6 and the broil element 14 which; 3. In an electric circuit for cooking appliances are constructed of the more ordinary oven heathaving a source of electric power, the combinaing element form adapted to carry the full line ti0n-of,a multi-partbaking element adapted to voltage. As disclosed herein, the electric, circuit 15 beloQa-ted-inthe lower) portion of the appliance, is adapted for use in conjunction with cooking one part ofsaidrelement having a higher resistappliances having a two-wire power system but. ance value than the other, a broiling element it will be understood that a three-wire system adapted to be located in the upper portion of could be used if desired. Moreover, many t the appliance, and switching means arranged in changes can be made in the arrangement and one position thereof to connect said higher recombinationof parts and inv the details of consistancepart to the source in series -.circuit:with2" struction herein disclosed within the scope of l saidbroilingelementand saidother partin parthe appended claims without departingfrom the allel therewith, in. another position thereof to spirit of the invention. connect only said other part to the source. and 1*;

I claim: said broiling element in-parallel-therewith; and l-,

1. In an electric circuit for cooking appliances. in a thi d position to connect only said broilingv having a SOUICflDf electric power, the combinae ementto the Source. tion ofa multi-part baking element, a, broiling w VICTOR WEBER. 1 element,-and switching means arranged in one position thereof to connect both said elements to REFERENCES CITED the source, in another positionthereof to connect The following referencesare .oflarecordzin-ith i w only-one part of said mu-lti-part element and said file of t t t; broiling element-to the source in parallel; and in, e

a third position to connect only said broiling ele-- UNITEDISTATES PATENTS inent to the source.- l Number Name Datedu:

2. Inanelectric circuit for cooking appliances 2,218,778 Weimer Oct.-'22, 19 having ansourceiof electric powerhthe combina- ,v 2,310,543 Pear e F b -9;;1943:; 

